Diiodohydroxyquinoline

Endpoint summary

Additional information

Appearance/physical state/colour:

On the basis of physical observation and using the sense of smell, diiodohydroxyquinoline was found to be an organic light yellow colour powder with characteristic odour at 26ºC and 966 hPa.

Melting point/freezing point:

Melting point of diiodohydroxyquinoline was found to be 215°C at an atmospheric pressure of 966 hpa by capillary method.

There was no decomposition & sublimation observed for diiodohydroxyquinoline at the melting point. Melting point value at 101325 Pa is equivalent to 225.51 °C.

Some of the other authoritative supporting sources of information indicates the decomposition of the substance at melting point. However, for the

purpose of the dossier as well as for the chemical safety report the experimental value of melting point (which is the key study) will be considered.

Boiling point:

Boiling point of diiodohydroxyquinoline was found to be 270°C an atmospheric pressure of 966 hpa by distillation method.

There was no decomposition observed for diiodohydroxyquinoline at the boiling point. Boiling point value at 101325 Pa is equivalent to 283.20 °C.

The other authoritative source of information indicate the boiling point to be in the range of 395.5 - 401.5 °C.However for the purpose of the dossier as well as for the chemical safety report, the boiling point of the key study which is 270°Cshall be considered.

Density:

Mass by volume method was used to derive the bulk density of the substance and the bulk density of diiodohydroxyquinoline was found to be 0.343 g/cm3 at 26 °C. This density value at 20°C is equivalent to 0.263 g/cm3.

Particle size distribution (Granulometry):

Based on the principle of measurement of relative amounts of particles present, sorted according to size, sieve analysis method have been used in this case and the particle size distribution (granulometry) of diiodohydroxyquinoline was found to be in the range of 75 micrometer to 500 micrometer. Majority of the particles were found to be in the size of 250 micrometer (45.4%).

Vapour pressure:

According to EPI (Estimation Programs Interface) Suite vapour pressure of diiodohydroxyquinoline is estimated as 0.0000000249 mm Hg at 25 deg C by Modified Grain Method. This value is equivalent to 0.00000332 Pa at 25 deg C.

Partition coefficient:

The experimental value of octanol water partition co-efficient (log Pow) of diiodohydroxyquinoline was found to be 0.602 at 26°C and pH of 4.7 by

shake-flask method. This value indicates that diiodohydroxyquinoline is relatively hydrophobic in nature.

The supporting study show value different from the key study which could be due to the difference in the estimation conditions. However for the purpose of the dossier and chemical safety assessment, the key study value shall be used.

Water solubility:

Water solubility of diiodohydroxyquinoline is found to be 1000 mg/L at 26°C by Shake flask method. This value indicates that diiodohydroxyquinoline is moderately soluble in water.

The supporting studies indicates values different from the key study which could be due to the difference in the estimation conditions. However for the purpose of the dossier and chemical safety assessment, the key study value shall be used.

Solubility in organic solvents / fat solubility:

Gravimetric method was used to determine the solubility of diiodohydroxyquinoline in organic solvent. The solubility of thediiodohydroxyquinoline in ethanol was found to be 400 mg/L at 26°C. This value is equivalent to 307.69 mg/L at 20 °C.

Using the Soxhlet/Solvent extraction method the solubility of diiodohydroxyquinoline in petroleum ether was found to be 40 mg/L at 26 °C.

Surface tension:

The surface tension of the compound diiodohydroxyquinoline is estimated to be 76.643997192 mN/m.

Flash point:

The substance diiodohydroxyquinoline does not ignite at 270°C and 966 hPa and hence it is considered as non flammable.

Auto flammability:

Diiodohydroxyquinoline did not catch fire on being exposed to air at room temperature of 26ºC and atmospheric pressure of 966 hPa. This indicates that diiodohydroxyquinoline is not auto-flammable.

Flammability:

Diiodohydroxyquinoline ignited only when the flame of bunsen burner having temperature of 950°C is brought in contact with it. Thus it can be concluded that diiodohydroxyquinoline is flammable only at high temperature of about 950°C. However since such high temperatures are not found under normal circumstances of transportation and use, diiodohydroxyquinoline is considered as non-flammable for chemical safety assessment.

Explosiveness:

According to theoretical considerations based on chemical structure, diiodohydroxyquinoline does not possess explosive or oxidizing properties. The reason for these is there are no chemical groups associated with explosive properties in diiodohydroxyquinoline. Thus, as per column 2 of Annex VII this information is not required.

Oxidising properties:

Diiodohydroxyquinoline is found to be oxidising with the redox titration yielding an end point of 206.7 ml KMno4 per 100g of analyte, diiodohydroxyquinoline.

Stability in organic solvents and identity of relevant degradation products:

Diiodohydroxyquinoline was found to be stable in organic solvent (dichloro methane) and no degradation products were formed as evident from the GC-MS chromatogram.

pH:

1% by volume solution of diiodohydroxyquinoline was found to exhibit a pH of 2.65 at 26°C. Thus 1% by volume solution of diiodohydroxyquinoline is acidic in nature.

Dissociation constant:

The average experimental pKa value for diiodohydroxyquinoline was found to be 0.00001937 at 26 °C indicating that it has dissociating properties. This value at 20°C is equivalent to 0.0000149.

The other authoritative source of information though indicate the pka value in the range of 2.4 to 8. However for the purpose of the dossier as well as for the chemical safety report, the pka of the key study which is 0.00001937at 26 °C shall be considered.

Viscosity:

This end point was considered for waiver as viscosity is an inherent property of liquid substances and diiodohydroxyquinoline is an organic solid. Therefore, testing for this end point was considered scientifically unjustified and considered for waiver.